NZ condemns North Korean nuclear test

The New Zealand government has joined a chorus of nations condemning a reported nuclear weapons test by North Korea.

The secretive North Korean government on Wednesday announced it had conducted a "successful" underground hydrogen bomb test, shortly after a large earthquake near one of its known testing sites.

If confirmed, the test would be the fourth by the country since 2006 and the first to use the more powerful hydrogen bomb.

New Zealand Duty Minister Sam Lotu-Iiga called the attack highly provocative and irresponsible.

"The test would run contrary to the recent efforts at dialogue on the Korean peninsula and flies in the face of the international community's calls for North Korea to abandon its nuclear weapon programs," he said.

"This action also flouts UN Security Council resolutions which have demanded that North Korea not conduct any further nuclear tests."

An emergency UN meeting is planned for early Thursday (AEDT).

"New Zealand will work with other Security Council members to make sure there is a strong response to this latest provocation," Mr Lotu-Iiga said.

New Zealand joined Australia, Japan, Britain, and South Korea in quickly condemning the reported test, along with China's state news agency, Xinhua, which called it "undesirable and unwise".